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September 2015    Download the Entire Issue (PDF) Available to the Public Vol. 30, No. 9   RSS Feed for Undercurrent Issues
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This Sunscreen May Indeed Have No Effect on Marine Life

from the September, 2015 issue of Undercurrent   Subscribe Now

Slathering on sunscreen is good for skin protection, but as we've previously written, studies have shown that certain ingredients in sunscreen and other skincare products have been proven highly toxic to corals and marine life. According to NOAA's National Centers for Coastal Ocean Science, even low concentrations of BP-2, used to protect skin against damaging ultraviolet rays, can quickly kill juvenile corals.

While on a Palau liveaboard, Autumn Blum, an avid diver from Tampa, FL, hated watching sunscreen residue and suds from shampoos and conditioners wash overboard after a dive. "The chemist in me knew what the ingredients were, and it was a little troubling," she said. So she decided to create a line of natural body products that was good for both humans and the environment. But as she found out, even "organic" ingredients aren't great for marine life -- her first three natural shampoo products killed every fish in the trial tank.

She contacted professors at Eckerd College in St. Petersburg, her alma mater, to do research more targeted than standard tests. They started with testing shampoo products. "We didn't want to just dump a bunch of shampoo into the tank, we wanted to be thoughtful about the concentration," said biology professor Denise Flaherty. Once that concentration was determined, the team wanted to know more than if the fish lived or died, they wanted to keep marine life free from any effect of the products, so their research focused on the changing swimming and feeding habits of the fish. Each product was tested on a tank of zebrafish and compared to a product-free tank of zebrafish. Tanks were checked daily for dead fish, as well as those swimming erratically or not eating. Blum's sunscreens passed the first phase with flying colors, even at the highest concentration tested: no dead fish in a tank with the equivalent of an ounce of sunscreen in three bathtubs full of water.

Another group of researchers tackled the coral testing. Eckerd professor Koty Sharp took student divers to collect corals for the lab. When the corals released larvae, the larvae were placed into dishes containing substrates that have been proven to be attractive to the larvae. "We don't know yet how sunscreen in reef water could influence coral larval settlement," says Koty Sharp. "However, we know that even a very small concentration of some chemicals can influence bacterial metabolism on these surfaces." To see how much sunscreen can be released from divers onto a reef, Sharp's team is doing further research.

With the results of her Eckerd lab testing, Blum thinks she has the right combination of marine- and humanfriendly ingredients. Her Stream2Sea line of products (sunscreen, hair products, body lotions and lip balm) are just rolling out in health food stores and outdoor retailers, but you can buy them online at

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